Depending on the installation position of the receiving antenna, its orientation can be specified within more or less narrow limits by the features of the installation position. In many cases, e.g. if the receiving antenna is to be attached to the roof of a vehicle, it is advantageous to orientate the same so that it is optimized for a vertically or at least predominantly vertically polarized reception signal. The expression “vertical” is to be understood within the scope of the present invention as synonymous with “perpendicular to the surface of the Earth”.
The electronics of transmission arrangements typically include a circuit board that is built into the key housing. Therefore it is advantageous to use a very flat housing for this purpose, so that the key has a flat design and is thus well suited to be stored, especially if it is carried on the body, e.g. in an item of clothing. Transmission arrangements with such a flat construction are normally held during the transmission operation so that the circuit board is approximately oriented parallel to the surface of the Earth.